Why can't we shake off certain songs?

In 1979, writing in Psyche, one of the world’s foremost periodicals on neuroscience, German psychiatrist Cornelius Eckert wanted to get something off his mind. “Melodies,” he wrote in thick technical German, “With and without text, which impose themselves to the inner ear obsessively, as unrecognisable articulations of potentially interpreted wishful impulses.” Kylie Minogue said it better with a chorus of 'Na na na nas' ad nauseam.

They're songs you just can't get of your head. Ohrwürmer, Eckert called them, ‘earworms’ in English. 36 years on and those catchy snippets of pop songs still burrow their way into our heads, uninvited, refusing to leave, and playing over and over again.

There is no exact science to figuring out just why certain songs get stuck in our heads and play on repeat for days, months, and even in the rarest of cases, years. But earworms reveal the inner workings of the parts of the brain we have no control over, an annoyingly catchy reminder that the brain does what it wants, repeating on and on.

Repetition might well be the key here, as it plays a significant role in how we remember things in the first place. Music, sounds containing both rhythm and pitch, is punctuated by repetition and melody, composed to impose on the listener’s mind. An earworm is just a particular verse or specific hook in a tune, a looping musical memory that lasts between 15 and 30 seconds. And the more you hear it, the more you remember it.

Contemporary musicologists and neuroscientists call earworms ‘Involuntary Musical Imagery’ (IMI), and researchers believe that they finally know what it is that forces a song inside your inner ear; songs that feature closely spaced notes on the musical stave and that linger slightly longer make for the most memorable of IMIs, and proved considerably harder to shake off.

On that note, Taylor Swift is an early bird for catching an earworm:

The chorus of her hit single Shake it Off is a prime example of the conditions that leave an IMI burrowing in your inner ear. After tapping your toes to the tune of Swift shrugging off those haters with her one-note repetitive long-beat declaration, you’ll be hard pressed to shake, shake, shake, shake, shake, shake it off, shake it off.

Another one is Koji Kondo’s iconic music from Super Mario. Kondo composes all of the music from the seminal Nintendo computer game, as well as the music from The Legend of Zelda, programming the catchy theme in what was then an extremely rudimentary piece of technology.

Everything about this is designed to stick, with Kondo’s music written in such a way that the beat of the music is repeated in the movements of all of the games characters. The rhythm even perfectly matches up with the glowing coin at the top of the screen, in a perfect storm of synthing beeps, destined to lodge itself inside your brain forever.

So when it comes to actually getting a tune out of your head, how can it actually be done? One proven method for breaking the cycle is to repeat a word at random, saying it over and over again in your head, in a process that neuroscientists refer to as ‘irrelevant sub-vocalisation’. Other than that, researchers at the University of Reading reckon that munching on some chewing gum also works, befuddling your brain with an easy activity that also interrupts the sound in your head with the sound of your own mastication.